Birth Control Health Center

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Is Your Birth Control as Safe as You Think?

Since NuvaRing hit the market, more than 700 women have filed lawsuits, claiming it has caused potentially life-threatening blood clots. The battle may change the way millions of women prevent pregnancy.

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Clot Control

A healthy woman's risk of a blood clot increases dramatically if she takes birth control with estrogen. Here's what you need to know to diagnose and prevent a clot:

• What is a blood clot? A tiny buildup of platelets and blood plasma proteins caused by decreased blood flow to the lower extremities. Pregnancy, obesity, or being squashed like a sardine on a flight to Hong Kong all allow blood to pool, which can lead to a clot. On top of that, estrogen from oral contraceptives increases the levels of four of the blood's 12 clotting factors, making clots more likely, says Barbara Dehn, a nurse practitioner with the Women Physicians OB/GYN Medical Group in Mountain View, California.

• Telltale symptoms: Cramplike leg pain and red, swollen, or warm skin. Chest pain, shortness of breath, and heart palpitations may signal a pulmonary embolism (meaning a piece of the clot has broken off and traveled to the lungs). If you have any of these symptoms, get to the emergency room. Doctors will give you blood-thinning drugs; in an extreme emergency, you'll get an injection of a "clot-busting" drug like TPA (tissue plasminogen activator).

• Preventive measures: Drinking 8 ounces of water every two hours when on a plane will make a clot less likely. And do five minutes of toe raises or calf flexes every hour while traveling, says Dr. Mark Melrose, an emergency room physician and cofounder of Urgent Care Manhattan, a walk-in medical practice in New York. If you're pregnant or have had a clot before, wear support stockings (thick, tight panty hose that encourages circulation). And don't smoke — it increases the risk by a factor of nine, according to one study.

• Genes count. Get a "clotting workup," a blood test to detect inherited clotting disorders like factor V Leiden or a protein C or S deficiency. The conditions are rare, but if a family member has had a clot, get tested. (It costs about $200 if your insurance doesn't cover it.) Dehn recently told a patient whose sister had had a clot-related stroke to take the test before starting birth-control pills with estrogen. It turned out she had factor V Leiden, an inherited clotting disorder found in, on average, 5 percent of Caucasians; 2 percent of Latinos; and 1 percent or fewer of African-Americans, Native Americans, and Asians. She chose a different birth control, totally "blown away she could've put her life at risk," says Dehn. — Sophia Banay Moura